1. Field of the Invention
The present invention relates to an electrophotographic image forming apparatus, in which a plurality of cartridges are removably mounted to an apparatus main body to form an image on a recording medium. Here, the electrophotographic image forming apparatus forms an image on a recording medium by using an electrophotographic image forming process. Then, examples of the electrophotographic image forming apparatus include, for example, an electrophotographic copying machine, an electrophotographic printer (for example, such as a laser beam printer and an LED printer), a facsimile machine, and a word processor. Besides, the recording medium is one on which an image is formed by the electrophotographic image forming apparatus, and paper, an OHT sheet, and the like are included therein, for instance. Further, a cartridge is, for example, a process cartridge or a developing cartridge, and contributes, under a state being removably mounted to a main body of the electrophotographic image forming apparatus, to an image forming process for forming the image on the recording medium. Here, in the above-mentioned process cartridge, at least one of a charging means, a developing means, and a cleaning means each serving as a process means and an electrophotographic photosensitive drum are integrated into a cartridge, and the thus formed cartridge is removably mounted to the main body. Therefore, a process cartridge, in which the developing means serving as the process means and the electrophotographic photosensitive drum are integrated into a cartridge, and the thus formed cartridge is removably mounted to the main body of the electrophotographic image forming apparatus, is also included in the above-mentioned process cartridge. Note that, the process cartridge, which integrally includes the electrophotographic photosensitive drum and the developing means, is referred to as a so-called integral type. Further, the process cartridge, which integrally includes the electrophotographic photosensitive drum and the process means other than the developing means, is referred to as a so-called separation type. That is, the developing means is provided in a developing unit, which is different from the process cartridge, and the image formation is performed through a pair of the developing unit and the process cartridge. This is referred to as the so-called separation type. In this case, the process cartridge allows mounting to and detaching from the main body by a user him/herself. Accordingly, maintenance of the apparatus main body may easily be performed. Note that, the process means acts on the electrophotographic photosensitive drum. Further, the developing cartridge refers to one, which includes a developing roller, contains a developer (toner) used to develop an electrostatic latent image formed on the electrophotographic photosensitive drum by the developing roller, and is removably mounted to the main body. In a case of the developing cartridge, the electrophotographic photosensitive drum is mounted to the apparatus main body or a cartridge supporting member described below. Alternatively, the electrophotographic photosensitive drum is provided in the so-called separation type process cartridge (in this case, the process cartridge has no developing means). Note that, the developing cartridge also allows mounting to and detaching from the main body by the user him/herself. Therefore, the maintenance of the apparatus main body may easily be performed. Then, as the cartridge, the so-called integral type or the so-called separation type process cartridge may be used. Further, as the cartridge, the so-called separation type process cartridge and the developing cartridge may be used as a pair. Further, there may include a case in which, as the cartridge, the electrophotographic photosensitive drum is fixed and mounted to the apparatus main body or the cartridge supporting member described below, and the developing cartridge is detachably used so as to be capable of acting on the electrophotographic photosensitive drum. Still further, the process cartridge or the developer cartridge containing a developer (toner) to be replenished to the developing cartridge, etc., is included in the above-mentioned cartridge.
2. Description of the Related Art
Hitherto, there is known the electrophotographic image forming apparatus, which forms an image on the recording medium using the electrophotographic image forming process. In the electrophotographic image forming apparatus, there is known the above-mentioned process cartridge system. Alternatively, there is known a developing cartridge system, which is constructed only by the above-mentioned developing unit as a separate member from the photosensitive drum. There is also known the above-mentioned developer cartridge system containing the developer. The above-mentioned process cartridge system, developing cartridge system, and developer cartridge system are all inclusively referred to as the cartridge systems. Note that, the above-mentioned process cartridge and developing cartridge each include a developer containing portion for containing the developer (toner) used to develop the electrostatic latent image. There is known a structure in which, in order to facilitate the replacement of the developer by the user, the drawer mounting the cartridge is provided so that the replacement work of various cartridges may be performed by pulling out the drawer from the apparatus main body to a predetermined position (US Patent Application Publication No. 2007/0160386). Further, there is also known a structure in which, when the drawer is pushed-in the apparatus main body, a friction member is abutted on the side surfaces of the drawer, thereby suppressing the energy of the drawer (US Patent Application Publication No. 2008/0181658). With this structure, a moving speed at the time of moving the drawer by the user is lowered, to thereby relax an impact which the drawer receives from the apparatus main body.